Integrative processes at intermediate levels are examined in specially favorable species, including electric fish, flat fish, catfish, sharks, porpoises, sloths, reptiles, octopus and others. Sensory information processing is emphasized including types of impulse coding, filtering, recognizing, commanding and organizing response systems. The role of electroreception and the central analysis of normal stimuli are under study. The comparative basis of EEG and evoked potentials in lower vertebrates and invertebrates is also under study.